RR.
With a serial number of 321XX, yours is another example of a SAC gun frame serial numbered out of sequence as regards production features, as the over-whelming number of 12-bore examples I've seen in the 32XXX up to about 32499 have been the Second Model SAC gun with fixed cocking hooks; and not a 3rd model with the sliding cocking hook feature seen on this example. But there are a fair number of examples, such as the C Grade in the DGJ article, I've seen that don't fit the standard mold (I also have an OO Grade 12-bore in the 21XXX range, and a 16-bore A Grade in the 28XXX range with the sliding cocking hook feature). The only real high-conditioned SAC guns I have at the moment are a Frist Model Grade OO and a Grade 3 gun; and I have a very nice Third Model Grade B 12-bore (I've owned a few others in the past). To be honest, I've not noticed any unusual finishes on barrel ribs; only that both top and bottom ribs were steel regardless of whether the barrel tubes were Damascus or fluid steel. Don't know why SAC used steel ribs on their Damascus guns as opposed to making them from Damascus as was standard procedure for so many other period makers; but thought the end result provided a nice contrast, which final appearance I must assume was created by whatever chemicals and finishing processes were used to high light the Damascus pattern (obviously had to finish the barrels after both ribs were soldered in place).
Woody, as regards the latest SAC DGJ article, I can assure everyone that the subject C Grade is an amazingly beautiful gun in spite of the pics; but readers will never know that because of the equally amazingly poor picture quality. Seems that the folks at the DGJ did not use the photos provided by Terry Allen; but instead used the captioned scans I had forwarded with the manuscript. I am unable to express in words my disgust with the end result; but apologize to the those members here who may be wondering what happened.
As to taking pics, I have no talent; which is why I work with Terry Allen. Glare is always an issue when photographing metal objects; so in working with Terry, I've asked how he deals with glare. Terry says glare can't be eliminated, so he uses additional lighting to equalize glare over the entire metal surface; a tricky procedure compounded by the combination of round and squared surfaces, and varying surface depths encountered on all shotgun frames. Photo sessions usually take several hours; and Terry is constantly snapping photos, adjusting lighting, and checking the result before finally getting the finished look as regards lighting, detail, and color that is acceptable to him.